a Field of the Invention
The present invention relates to a photosensitive element for use in electrophotography, and more particularly it relates to a novel electrophotographic element having a photosensitive layer containing a disazo pigment as effective component.
b Description of the Prior Art
There have hitherto been developed various electrophotographic sensitive elements comprising an electroconductive support and a photosensitive layer formed thereon containing some azo pigment as effective component. For instance, Japanese Patent Publication No. 16474/1969 (U.S. Ser. No. 445,194 now abandoned) discloses an electrophotographic sensitive element employing some monoazo pigment, and Japanese Laid-Open Unexamined Patent Application No. 37543/1972 (U.S. Pat. No. 3,898,084) discloses an electrophotographic element employing some disazo pigment. These azo pigments employed in the prior art are admittedly useful materials to serve as an effective component of electrophotographic elements, but when the various requirements for electrophotographic elements from the view point of the electrophotographic process are taken into consideration, there has, in fact, not been developed any photosensitive element that will meet these requirements satisfactorily. Therefore, it is important to provide a wide variety of pigments useful as effective component, without limiting to azo pigments, so as to permit a wide range of selection. By so doing, it becomes possible to provide an electrophotographic element apposite to a specific process. In other words, for the electrophotographic processes, it is desirable that the variety of pigments to serve as effective component of the electrophotographic elements should be as wide as possible.